Nose structure for an aircraft

ABSTRACT

A nose structure of an aircraft includes an airframe. A wheel well assembly is coupled to the airframe and forms a portion of a nose landing gear bay. The wheel well assembly includes a pressure deck that extends from a right side of the airframe to a left side of the airframe and that forms a portion of a pressure boundary delimiting a pressurized space and a non-pressurized space. A floor-panel support is supported by the pressure deck in the pressurized space. The pressure deck and the floor-panel support form a portion of a flight deck floor of a flight deck of the aircraft. A plurality of transport elements is located between the floor-panel support and the pressure deck. The plurality of transport elements is associated with at least one high-level system of the aircraft.

FIELD

The present disclosure is generally related to structures of aircraftand, more particularly, to a nose structure for an aircraft that uses awheel well assembly to form a portion of a floor, form a nose landinggear bay, and delimit a pressurized space and a non-pressurized space ofthe aircraft.

BACKGROUND

An aircraft for transport of passengers and freight includes a fuselagethat is usually separated into at least one pressurized space and atleast one non-pressurized space. The pressurized space includes zonesthat require pressurization during flight, such as a flight deck for theflight crew, a cabin for the passengers, and a cargo hold for baggageand other varied cargo. The non-pressurized space includes zones that donot require pressurization during flight, such as storage compartmentsfor landing gear. Typically, an aircraft includes two main landing gearsthat are typically placed under the wings and a nose landing gear thatis centered under the front end of the fuselage. A storage compartmentfor the nose landing gear is typically located under the floor of theaircraft. Conventional nose landing gear storage compartments includetwo discrete components: a support structure that must be strong enoughto withstand stresses applied to the nose landing gear and strong enoughto transfer loads from the nose landing gear into the forward fuselage;and a pressure barrier that forms a boundary between the pressurizedspace and the non-pressurized space of the fuselage. Additionally, thespace between the support structure, the pressure barrier, and thefuselage typically houses various operational components of theaircraft. However, this space is difficult to access and accounts for asignificant waste of volume in the fuselage.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of pressure barriers for aircraft and,more particularly, to pressure barriers that delimit a nose landing gearstorage compartment.

SUMMARY

The following is a non-exhaustive list of examples, which may or may notbe claimed, of the subject matter according to the present disclosure.

In an example, a disclosed nose structure of an aircraft includes anairframe and a wheel well assembly. The wheel assembly is coupled to theairframe and forms a portion of a nose landing gear bay. The wheel wellassembly includes a pressure deck. The pressure deck extends from aright side of the airframe to a left side of the airframe. The pressuredeck forms a portion of a pressure boundary delimiting a pressurizedspace and a non-pressurized space.

In another example, the disclosed nose structure of an aircraft includesan airframe. The airframe includes a pressure deck that forms a portionof a pressure boundary delimiting a pressurized space and anon-pressurized space. The nose structure also includes a floor-panelsupport that is supported by the pressure deck 118 in the pressurizedspace. The nose structure further includes a plurality of operationalcomponents, located in the pressurized space between the floor-panelsupport and the pressure deck. The plurality of operational componentsis associated with at least one high-level system of the aircraft.

In an example, a disclosed aircraft includes an airframe, forming a nosestructure of the aircraft, and at least one high-level system. Theaircraft also includes a wheel well assembly, coupled to the airframeand forming a portion of a nose landing gear bay. The wheel wellassembly includes a pressure deck that extends from a right side of theairframe to a left side of the airframe and that forms a portion of apressure boundary delimiting a pressurized space and a non-pressurizedspace. The aircraft further includes a floor-panel support, supported bythe pressure deck. The aircraft also includes a plurality of transportelements, located between the floor-panel support and the pressure deck.The pressure deck and the floor-panel support form a portion of a floorof the aircraft that delimits a flight deck, arranged over the floor inthe pressurized space, and the nose landing gear bay, arranged under thefloor in the non-pressurized space. The plurality of transport elementsis in communication with the at least one high-level system. Theplurality of transport elements is accessible from within the flightdeck.

In an example, a disclosed airframe of an aircraft includes an externalskin. The airframe also includes a first bulkhead, coupled to theexternal skin running transversely between a right side of the airframeand a left side of the airframe. The airframe further includes a secondbulkhead, longitudinally spaced away from the first bulkhead and coupledto the external skin running transversely between the right side of theairframe and the left side of the airframe. The airframe also includes apressure deck, coupled to the first bulkhead, the second bulkhead, andthe external skin running longitudinally between the first bulkhead andthe second bulkhead and running transversely between the right side ofthe airframe and the left side of the airframe. The pressure deck, thefirst bulkhead, and the second bulkhead at least partially delimit apressurized space and a non-pressurized space of the aircraft.

In another example, the disclosed aircraft includes a fuselage, at leastone high-level system, and a floor. The floor includes a pressure deck,coupled to the fuselage and forming at least a portion of a pressureboundary delimiting a pressurized space and a non-pressurized space. Thefloor also includes a floor-panel support, supported by the pressuredeck in the pressurized space. The floor further includes a plurality oftransport elements, located between the floor-panel support and thepressure deck. The plurality of transport elements is in communicationwith the at least one high-level system of the aircraft.

In another example, the discloses aircraft includes an airframe and awheel well assembly, coupled to the airframe. The wheel well assemblyand the airframe form a nose landing gear bay. The aircraft alsoincludes a nose landing gear that is stowable within the nose landinggear bay. The nose landing gear includes a trunnion, coupled to thewheel well assembly. The nose landing gear also includes a strut,coupled to the trunnion. The nose landing gear further includes an axle,coupled to the strut, opposite to the trunnion. The nose landing gearalso includes a wheel, coupled to the axle. With the nose landing gearstowed within the nose landing gear bay, the axle is located closer to acentral longitudinal axis of the aircraft than the trunnion.

In an example, a disclosed method of making an aircraft includes stepsof: (1) assembling a subfloor assembly, including a floor-panel supportand plurality of transport elements; (2) coupling a wheel well assemblyto an airframe of the aircraft to form a nose landing gear bay of theaircraft; and (3) coupling the subfloor assembly to the wheel wellassembly to form a portion of a floor of the aircraft so that theplurality of transport elements is located between the floor-panelsupport and the wheel well assembly.

In another example, the disclosed method of making an aircraft includessteps of: (1) coupling a wheel well assembly to an airframe of theaircraft; (2) forming a nose landing gear bay from the wheel wellassembly and the airframe; (3) coupling a nose landing gear to the wheelwell assembly; and (4) stowing the nose landing gear within the noselanding gear bay so that an axle of the nose landing gear is locatedcloser to a central longitudinal axis of the aircraft than a trunnion ofthe nose landing gear.

In another example, the disclosed method of making an aircraft includessteps of: (1) coupling a pressure deck to an airframe of the aircraft,wherein the pressure deck extends from a right side of the airframe to aleft side of the airframe; (2) coupling a nose landing gear box to thepressure deck and to the airframe, wherein the nose landing gear box islocated rearward of the pressure deck; (3) forming a portion of apressure boundary that delimits a pressurized space and anon-pressurized space of the aircraft with the pressure deck, the noselanding gear box, and the airframe; (4) forming a portion of a noselanding gear bay of the aircraft, located in the non-pressurized space,with the pressure deck, the nose landing gear box, and the airframe; (5)coupling a floor-panel support to the pressure deck and to the noselanding gear box in the pressurized space to form a flight deck floor ofa flight deck above the nose landing gear bay; (6) accessing an interiorvolume of the aircraft, located between the nose landing gear box andthe airframe, from within the flight deck through the floor-panelsupport.

In an example, a disclosed method of accessing a portion of an aircraftincludes steps of: (1) entering an interior volume of the aircraft,formed by an airframe, a wheel well assembly, coupled to the airframe,and a floor panel-support, coupled to the wheel well assembly, throughthe floor-panel support; and (2) accessing at least a portion of thewheel well assembly from within the interior volume.

Other examples of the disclosed airframe structure, aircraft, and methodwill become apparent from the following detailed description, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an example of an aircraft;

FIG. 2 is a schematic, side elevational view, in partial cutaway, of anexample of a nose structure of the aircraft;

FIG. 3 is a schematic, side elevational view, in partial cutaway, of anexample of the nose structure of the aircraft;

FIG. 4 is a schematic, side elevational view, in partial cutaway, of anexample of the nose structure of the aircraft;

FIG. 5 is a schematic, sectional view of the nose structure of theaircraft, on line 5-5 of FIG. 3;

FIG. 6 is a schematic, sectional view of the nose structure of theaircraft, on line 6-6 of FIG. 3;

FIG. 7 is a schematic, sectional view of the nose structure of theaircraft, on line 7-7 of FIG. 3;

FIG. 8 is a schematic, sectional view of the nose structure of theaircraft, on line 8-8 of FIG. 3;

FIG. 9 is a schematic, top plan view of an example of the nose structureof FIG. 8 with a subfloor assembly removed;

FIG. 10 is a schematic, bottom perspective view of an example of a wheelwell assembly of the aircraft;

FIG. 11 is schematic, bottom perspective view of an example of the nosestructure of the aircraft;

FIG. 12 is a schematic, side perspective, sectional view, in partialcutaway, of the nose structure of the aircraft;

FIG. 13 is a schematic, exploded, top perspective view of an example ofthe subfloor assembly and the wheel well assembly of the aircraft;

FIG. 14 is a schematic, top perspective view of an example the subfloorassembly and the wheel well assembly of the aircraft;

FIG. 15 is a flow diagram of an example of a method for making anaircraft;

FIG. 16 is a flow diagram of an example of the method of making anaircraft;

FIG. 17 is a flow diagram of an example of the method of making anaircraft;

FIG. 18 is a flow diagram of an example of a method of accessing aportion of an aircraft;

FIG. 19 is a flow diagram of an aircraft manufacturing and servicemethodology;

FIG. 20 is a front and side perspective view of a nose section of anaircraft, depicting the ornamental design thereof;

FIG. 21 is a left side view of the nose section of an aircraft of FIG.20;

FIG. 22 is a right side view of the nose section of an aircraft of FIG.20;

FIG. 23 is a front view of the nose section of an aircraft of FIG. 20;

FIG. 24 is a rear view of the nose section of an aircraft of FIG. 20;

FIG. 25 is top view of the nose section of an aircraft of FIG. 20; and

FIG. 26 is a bottom view of the nose section of an aircraft of FIG. 20.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings,which illustrate specific examples described by the present disclosure.Other examples having different structures and operations do not departfrom the scope of the present disclosure. Like reference numerals mayrefer to the same feature, element, or component in the differentdrawings.

Illustrative, non-exhaustive examples, which may be, but are notnecessarily, claimed, of the subject matter according the presentdisclosure are provided below. Reference herein to “example” means thatone or more feature, structure, element, component, characteristic,and/or operational step described in connection with the example isincluded in at least one embodiment and/or implementation of the subjectmatter according to the present disclosure. Thus, the phrases “anexample,” “another example,” “one or more examples,” and similarlanguage throughout the present disclosure may, but do not necessarily,refer to the same example. Further, the subject matter characterizingany one example may, but does not necessarily, include the subjectmatter characterizing any other example. Moreover, the subject mattercharacterizing any one example may be, but is not necessarily, combinedwith the subject matter characterizing any other example.

Referring generally to FIGS. 1-14, by way of examples, the presentdisclosure describes an aircraft 100, an airframe 102 of the aircraft100, and a nose structure 160 of the aircraft 100. More specifically,the present disclosure describes examples of a wheel well assembly 194that forms a portion of a nose landing gear bay 124 of the aircraft 100,a portion of a floor 204 of the aircraft 100, and a portion of apressure boundary 104 that delimits a pressurized space 106 andnon-pressurized space 108. The configuration of the disclosed nosestructures 160 beneficially improves aerodynamic performancecharacteristics of the aircraft 100, reduces the weight of the aircraft100, reduced assembly time and cost of the aircraft 100, reducesrecurring costs associated with inspection and maintenance of theaircraft 100, and improves access to areas around the nose landing gearbay 124.

FIG. 1 schematically illustrates an example of an aircraft 100. In theillustrative example, the aircraft 100 is a fixed-wing aircraft. Inother examples, the aircraft 100 has any one of various otherconfigurations. The aircraft 100 includes an airframe 102. The airframe102 forms a framework of a fuselage 130 and a pair of wings 162 of theaircraft 100. In the illustrative example, the fuselage 130 includes anose structure 160, at least one cylindrical barrel section 246, and atail 170.

The aircraft 100 includes a central longitudinal axis 188 and atransverse axis 220. The central longitudinal axis 188 runs through acenter of the fuselage 130 from a forward end of the aircraft 100 to anaft end of the aircraft 100. For example, the central longitudinal axis188 runs through a center of a section cut of the cylindrical barrelsection 246 of the fuselage 130. The transverse axis 220, also referredto as a lateral axis, runs from a left side of the aircraft 100 to aright side of the aircraft 100 and is perpendicular to the centrallongitudinal axis 188.

Throughout the present disclosure, a relative location of a structure,element, or component of the aircraft 100 may be referred to as being“forward of,” “aft of,” or “rearward of” another structure, element, orcomponent. As used herein, the terms “forward,” “front,” “aft,” “rear,”and similar terms have their ordinary meaning as known to those skilledin the art and refer to positions relative to a direction of movement ofthe aircraft 100. Similarly, as used herein, the term “forwarddirection” refers to a direction running from an aft location to aforward location and the term “rearward direction” refers to a directionrunning from a forward location to an aft location.

Throughout the present disclosure, a relative position and/ororientation of a structure, element, or component of the aircraft 100may be described in an orthogonal frame of reference of axes X, Y, Z(FIGS. 1 and 2). For example, the central longitudinal axis 188 isparallel to the X-axis and the transverse axis 220 is parallel to theY-axis. As used herein, the terms “horizontal,” “horizontally,” andsimilar terms refer to a structure, element, or component being parallelto the XY-plane. The terms “vertical,” “vertically,” and similar termsrefer to a structure, element, or component being perpendicular to theXY-plane. Throughout the present disclosure, horizontal and verticalalso include approximately horizontal and approximately vertical,respectively.

As used herein, the term “approximately” refers to or represents acondition that is close to, but not exactly, the stated condition thatstill performs the desired function or achieves the desired result. Asan example, the term “approximately” refers to a condition that iswithin an acceptable predetermined tolerance or accuracy. For example,the term “approximately” refers to a condition that is within 10% of thestated condition. However, the term “approximately” does not exclude acondition that is exactly the stated condition.

The fuselage 130 is the main body of the aircraft 100 and forms aninterior 164 of the aircraft 100. The interior 164 is configured to holda flight crew, one or more passengers, and/or cargo. In the illustrativeexample, the fuselage 130 is an elongate, generally cylindricalfuselage.

The nose structure 160 of the aircraft 100 forms a front portion (orforward end) of the fuselage 130, the tail 170 forms a rear portion (oraft end) of the fuselage 130, and the cylindrical barrel section 246forms an intermediate portion of the fuselage 130. In an example, thenose structure 160 includes a portion of the fuselage 130 running fromthe cylindrical barrel section 246 (e.g., a constant cross-sectionalportion) of the fuselage 130 to a tip 218 of a nose of the fuselage 130and having a variable cross-section, viewed along the centrallongitudinal axis 188. In another example, the nose structure 160includes a forwardmost segment of a multi-segment fuselage 130 thatincludes a flight deck 122 (FIG. 3) and a nose landing gear bay 124(FIG. 3). The tail 170 may include at least one vertical stabilizerand/or at least one horizontal stabilizer.

The aircraft 100 also includes a set of retractable landing gear (notshown in FIG. 1). The set of landing gear includes two main landinggears (not shown in the Figures) and a nose landing gear 136 (FIG. 3).Each landing gear is articulated to support the aircraft 100 on theground and to be retracted after takeoff. The two main landing gears aretypically located under the wings 162. The nose landing gear 136, alsocommonly referred to as the front landing gear, is typically locatedunder the front portion (e.g., the nose) of the fuselage 130 andcentered along the central longitudinal axis 188.

The aircraft 100 also includes a plurality of high-level systems 114.The high-level systems 114 include, but are not limited to, at least oneof an electrical system 150, a hydraulic system 152, an environmentalsystem 154, a communications system 156, a propulsion system 158, aflight control system 222, and a radar system 224. Any number of othersystems may also be included.

Referring to FIGS. 2-9, in an example, the nose structure 160 includesat least a portion of the airframe 102 of the aircraft 100. In FIG. 2, aportion of an external skin 174 of the airframe 102 is cutaway to showthe wheel well assembly 194 and the floor 204 of the aircraft 100. InFIGS. 3 and 4, certain portions of the airframe 102 (e.g., frames 172)are not shown for clarity of illustration.

Referring to FIG. 2, in an example, the airframe 102 includes aplurality of frames 172. The frames 172 are the main structural membersof the fuselage 130 and establish the shape of the fuselage 130. Theframes 172 include annular members or semi-annular members that areperpendicular to and extend circumferentially around the centrallongitudinal axis 188 of the fuselage 130. The frames 172 arelongitudinally spaced apart along the central longitudinal axis 188.

The external skin 174 is coupled to the frames 172 and extendscircumferentially around the central longitudinal axis 188. Typically,the external skin 174 includes a plurality of skin panels. In someexamples, the airframe 102 also includes a plurality of stiffeningmembers (not shown in the Figures), commonly referred to as stringers.The stiffening members are coupled to an interior surface of theexternal skin 174 and to the frames 172. The stiffening members areoriented generally parallel to each other and extend generally parallelto the central longitudinal axis 188 of the fuselage 130.

Referring to FIGS. 2-14, in an example, the nose structure 160 includesthe airframe 102 and the wheel well assembly 194. The wheel wellassembly 194 is coupled to the airframe 102. The wheel well assembly 194forms a portion of a nose landing gear bay 124 (FIGS. 2-6). The wheelwell assembly 194 includes a pressure deck 118. The pressure deck 118extends from a right side 198 of the airframe 102 to a left side 200 ofthe airframe 102, as illustrated in FIGS. 6, 8, and 9. The pressure deck118 forms a portion of a pressure boundary 104 delimiting a pressurizedspace 106 and a non-pressurized space 108.

Referring to FIGS. 2-4, 6, 8 and 12-14, in an example, the nosestructure 160 also includes a floor-panel support 110. The floor-panelsupport 110 is supported by the pressure deck 118 in the pressurizedspace 106, as illustrated in FIGS. 2-4 and 6. The pressure deck 118 andthe floor-panel support 110 form a portion of a flight deck floor 120 ofthe flight deck 122 (also commonly referred to as a cockpit) of theaircraft 100, as illustrated in FIGS. 2-4 and 6.

Referring to generally to FIGS. 2-4 and particularly to FIGS. 5, 6, 8and 12-14, in an example, the nose structure 160 further includes aplurality of transport elements 112 (FIGS. 5, 6, 8 and 12-14). Theplurality of transport elements 112 is located between the floor-panelsupport 110 and the pressure deck 118. The plurality of transportelements 112 is associated with at least one of the high-level systems114 (FIG. 1) of the aircraft 100. In FIGS. 2-4, the plurality oftransport elements 112, located between the floor-panel support 110 andthe pressure deck 118, is not shown for clarity of illustration.

The wheel well assembly 194 facilitates connection of the nose landinggear 136 to the airframe 102 and stowage of the nose landing gear 136within the nose landing gear bay 124 when the nose landing gear 136 isretracted. The wheel well assembly 194 also facilitates the transfer ofloads transmitted by the nose landing gear 136 to the airframe 102. Theconnection interfaces between the wheel well assembly 194 and theairframe 102 (e.g., the external skin 174) create the pressure boundary104 that delimits the pressurized space 106 and the non-pressurizedspace 108. Supporting the floor-panel support 110 with the pressure deck118 of the wheel well assembly 194 to form the flight deck floor 120 andlocating the plurality of transport elements 112 (FIGS. 5, 6, and 8)between the floor-panel support 110 and the pressure deck 118 optimizesthe space available in the nose structure 160 and reduces the volumerequired by the nose structure 160 to accommodate the plurality oftransport elements 112 and the nose landing gear bay 124.

As used herein, the term “pressurized space” refers to a space that isconfigured to be or that is capable of being pressurized when theaircraft 100 is at altitude. As used herein, the term “non-pressurizedspace” refers to a space that is not configured to be or that is notcapable of being pressurized. As used herein, the term “pressureboundary” refers to an interface or joint between structures that servesas a pressure barrier between a pressurized space and a non-pressurizedspace. For example, two structures that are coupled together andhermetically closed (e.g., sealingly coupled) form a pressure boundarythat can withstand a pressure differential.

As illustrated in FIG. 3, in an example, the aircraft 100 includes theflight deck 122, a passenger compartment 166, a cargo compartment 168,and the nose landing gear bay 124. The floor 204 separates the fuselage130 into the flight deck 122 and the passenger compartment 166, whichare located above the floor 204, and the cargo compartment 168 and thenose landing gear bay 124, which are located below the floor 204. In anexample, the floor 204 includes the flight deck floor 120 and apassenger deck floor 202. The flight deck floor 120 forms the main deckof the flight deck 122 and separates the flight deck 122 and the noselanding gear bay 124. The passenger deck floor 202 forms the main deckof the passenger compartment 166 and separates the passenger compartment166 and the cargo compartment 168. In an example, the pressurized space106 forms the flight deck 122, the passenger compartment 166, and thecargo compartment 168. The non-pressurized space 108 forms the noselanding gear bay 124.

Referring to FIGS. 8 and 12-14, in an example, the floor-panel support110 includes a plurality of beams 244. In an example, a portion of theplurality of beams 244 runs longitudinally and another portion of theplurality of beams 244 runs transversely to form a grid pattern. In anexample, the plurality of floor panels 116 is supported by and iscoupled to the plurality of beams 244. In an example, at least a portionof the plurality of transport elements 112 is coupled to the pluralityof beams 244.

Referring to FIGS. 3-5, in an example, the passenger deck floor 202includes a plurality of floor beams 240. The plurality of floor beams240 run transversely between the right side 198 (FIG. 5) of the airframe102 to the left side 200 (FIG. 5) of the airframe 102 and arelongitudinally spaced apart from each other. A plurality of passengerdeck floor panels 242 are supported by and coupled to the plurality offloor beams 240. As illustrated in FIGS. 4 and 5, in an example, aforward portion of the passenger deck floor 202 is supported by thewheel well assembly 194.

Referring generally to FIGS. 2-4 and 8, and particularly to FIGS. 12-14,in an example, the plurality of transport elements 112 is coupled to thefloor-panel support 110 to form a subfloor assembly 208. The subfloorassembly 208 is coupled to the pressure deck 118 within the airframe102.

Thus, in an example, assembly of the floor-panel support 110 andcoupling of the plurality of transport elements 112 to the floor-panelsupport 110 is performed prior to installation of the subfloor assembly208 within the airframe 102. The plurality of transport elements 112 andthe floor-panel support 110 are constructed as a unitary, or integrated,component (i.e., the subfloor assembly 208) outside of the airframe 102.The subfloor assembly 208 is then transported and installed within theairframe 102 (within the nose structure 160). A layout and/or selectionof the plurality of transport elements 112 may be based on a design ofthe aircraft 100 and/or the high-level systems 114 to which theplurality of transport elements 112 is to be coupled. This approachbeneficially improves the cycle time and reduces the costs associatedwith manufacture of the aircraft 100.

Referring generally to FIGS. 2-4, and particularly to FIGS. 12-14, in anexample, the nose structure 160 includes a plurality of floor panels116. In FIGS. 12-14, only a portion of the plurality of floor panels 116is shown. The plurality of floor panels 116 is support by and is coupledto the floor-panel support 110. The plurality of floor panels 116 coverthe plurality of transport elements 112. At least a portion of theplurality of floor panels 116 is removable from the floor-panel support110 to access the plurality of transport elements 112 from within theflight deck 122.

Thus, the floor panels 116 serve as finish flooring and form a portionof the flight deck floor 120. Selective removal of a portion of theplurality of floor panels 116 provides access to the plurality oftransport elements 112, located between the floor-panel support 110 andthe pressure deck 118, through the floor-panel support 110, such asduring assembly, inspection, and/or maintenance. This approachbeneficially simplifies access to the plurality of transport elements112, which is accessible from above the pressure deck 118, rather thanbeneath it, as compared to traditional aircraft design in whichtransport elements and other operational components are in very confinedspaces between the nose landing gear bay and the fuselage. Additionally,selective removal of a portion of the plurality of floor panels 116 alsoprovides access to at least a portion of the wheel well assembly 194through the floor-panel support 110.

Referring to FIGS. 8,9,13, and 14, in an example, the pressure deck 118includes a platform 144 and a plurality of support beams 146. Theplurality of support beams 146 is coupled to the platform 144. Thefloor-panel support 110 is supported by and is coupled to the pluralityof support beams 146.

Generally, the platform 144 of the pressure deck 118 is a panelstructure that is configured to support intended flight deck loads. Thepressure deck 118 (e.g., the panel structure) may also includestiffeners. As illustrated in FIG. 13, in an example, the plurality ofsupport beams 146 project vertically upward from a surface of theplatform 144 and provide structural support for placement and connectionof the floor-panel support 110. The plurality of support beams 146 spacethe floor-panel support 110 away from the platform 144 to accommodateplacement of the plurality of transport elements 112 between thefloor-panel support 110 and the platform 144.

Referring to FIGS. 9,13, and 14, in an example, each one of theplurality of support beams 146 extends longitudinally and istransversely spaced apart from an adjacent one of the plurality ofsupport beams 146. A portion of the plurality of transport elements 112is located between an adjacent pair 196 of the plurality of supportbeams 146.

As used herein, the terms “longitudinally,” “longitudinal,” and similarterms refer to being along (e.g., approximately parallel to) the centrallongitudinal axis 188 (FIGS. 1 and 2) of the aircraft 100. The terms“transversely,” “transvers,” and similar terms refer to being along(e.g., approximately parallel to) the transverse axis 220 (FIG. 1) ofthe aircraft 100.

As illustrated in FIGS. 13 and 14, in an example, at least a portion ofthe plurality of transport elements 112, coupled to an underside of thefloor-panel support 110, extends longitudinally along the floor-panelsupport 110. These longitudinally extending portions of the plurality oftransport elements 112 are positioned such that they fit between theadjacent pair 196 (FIG. 13) (e.g., side-by-side pair) of the pluralityof support beams 146. For example, a portion of one group of theplurality of transport elements 112 is located between one adjacent pair196 of the plurality of support beams 146 and a portion of another groupof the plurality of transport elements 112 is located between anotheradjacent pair 196 of the plurality of support beams 146. Any number ofthe transport elements 112 may be positioned between any adjacent pair196 of the plurality of support beams 146. As used herein, the phrase“number of” means one or more of a given item. For example, theplurality of transport elements 112 is arranged on, or is laid outrelative to, the floor-panel support 110 so that one or more transportelements 112 are positioned between a corresponding adjacent pair 196 ofsupport beams 146. This arrangement reduces the volume required forinstallation of the plurality of transport elements 112 by essentiallylocating the plurality of transport elements 112 within the floor 204 ofthe fuselage 130 (FIGS. 2-4).

Referring generally to FIGS. 5,6, and 8, and particularly to FIGS.12-14, in an example, the plurality of transport elements 112 includescommunication lines 148. The communication lines 148 are used for, orare associated with, at least one of the electrical system 150 (FIG. 1),the hydraulic system 152 (FIG. 1), the environmental system 154 (FIG.1), the communication system 156 (FIG. 1), the flight control system 222(FIG. 1), the radar system 224 (FIG. 1), or another one of thehigh-level systems 114 (FIG. 1) of the aircraft 100.

In an example, the communication lines 148 include electrical lines thattransfer electrical power, electrical signals, and/or data between twoor more electronic components that are in electrical communication witheach other, such as those associated with the electrical system 150, thecommunication system 156, the flight control system 222, and/or theradar system 224. In another example, the communication lines 148include hydraulic lines that transfer hydraulic fluid between two ormore hydraulic components that are in fluid communication with eachother, such as those associated with of the hydraulic system 152. Inanother example, the communication lines 148 include other types offluid transfer lines that transfer air, oxygen, or another fluid betweentwo or more environmental components that are in fluid communicationwith each other, such as those associated with of the environmentalsystem 154.

Referring to FIGS. 2-7 and 9-13, in an example, the wheel well assembly194 includes a first bulkhead 126 (not shown in FIGS. 5 and 6). Thefirst bulkhead 126 is coupled to the airframe 102 and runs transverselybetween the right side 198 of the airframe 102 and the left side 200 ofthe airframe 102, as illustrated in FIG. 7. The first bulkhead 126 formsa portion of the pressure boundary 104. The wheel well assembly 194 alsoincludes a second bulkhead 128 (not shown in FIGS. 5 and 7). The secondbulkhead 128 is coupled to the airframe 102 and runs transverselybetween the right side 198 of the airframe 102 and the left side 200 ofthe airframe 102, as illustrated in FIG. 6. The second bulkhead 128forms a portion of the pressure boundary 104. The first bulkhead 126 andthe second bulkhead 128 are longitudinally spaced apart from each other.The pressure deck 118 extends between and is coupled to the firstbulkhead 126 and the second bulkhead 128, as illustrated in FIGS. 2-4and 9-11.

Referring to FIGS. 2-5 and 9-13, in an example, the airframe 102 alsoincludes a nose landing gear box 134. The nose landing gear box 134 iscoupled with the second bulkhead 128 and the airframe 102. The noselanding gear box 134 forms a portion of the pressure boundary 104. Thenose landing gear 136 of the aircraft 100 is mountable within the noselanding gear box 134. In an example, the second bulkhead 128 isconfigured to react to a load transmitted by the nose landing gear 136through the nose landing gear box 134. For example, the second bulkhead128 transfers the load to the external skin 174 and/or the frames 172.

Referring to FIGS. 2-5 and 9-13, in an example, the wheel well assembly194 includes a third bulkhead 132. The third bulkhead 132 is coupled tothe airframe 102 and the nose landing gear box 134 and runs transverselybetween the right side 198 of the airframe 102 and the left side 200 ofthe airframe 102, as illustrated in FIG. 5. The third bulkhead 132 formsa portion of the pressure boundary 104. In an example, the thirdbulkhead 132 is configured to react to the load transmitted by the noselanding gear 136 through the nose landing gear box 134. For example, thethird bulkhead 132 transfers the load to the external skin 174 and/orthe frames 172.

Referring generally to FIGS. 2-6 and 9 and particularly to FIGS. 10-12,in an example, the nose landing gear box 134 is a three-sided structure.The nose landing gear box 134 is located aft of the second bulkhead 128.The nose landing gear box 134 includes a first sidewall 176. The firstsidewall 176 is coupled to the airframe 102, the second bulkhead 128,and the third bulkhead 132. The first sidewall 176 runs longitudinallybetween the third bulkhead 132 and the second bulkhead 128. The firstsidewall 176 forms a portion of the pressure boundary 104. The noselanding gear box 134 also includes a second sidewall 178. The secondsidewall 178 is coupled to the airframe 102, the second bulkhead 128,and the third bulkhead 132. The second sidewall 178 runs longitudinallybetween the third bulkhead 132 and the second bulkhead 128 and istransversely spaced away from the first sidewall 176. The secondsidewall 178 forms a portion of the pressure boundary 104. The noselanding gear box 134 further includes a top wall 180. The top wall 180extends between and is coupled to the first sidewall 176, the secondsidewall 178, the third bulkhead 132, and the second bulkhead 128. Thetop wall 180 forms a portion of the pressure boundary 104.

In an example, each one of the first bulkhead 126, the second bulkhead128, and/or the third bulkhead 132 is a panel structure that isconfigured to support intended loads. Each one of the first bulkhead126, the second bulkhead 128, and/or the third bulkhead 132 (e.g., thepanel structures) may also include stiffeners.

In an example, each one of the first sidewall 176, the second sidewall178, and/or the top wall 180 is a panel structure that is configured tosupport intended loads. Each one of the first sidewall 176, the secondsidewall 178, and/or the top wall 180 (e.g., the panel structures) mayalso include stiffeners.

In an example, the pressure deck 118 is coupled to and is sealed to theairframe 102, the first bulkhead 126, and the second bulkhead 128. Aportion of the pressure boundary 104 is formed by the sealed connectionbetween the pressure deck 118 and the airframe 102 (e.g., the externalskin 174 of the airframe 102). A portion of the pressure boundary 104 isformed by the sealed connection between the pressure deck 118 and thefirst bulkhead 126. A portion of the pressure boundary 104 is formed bythe sealed connection between the pressure deck 118 and the secondbulkhead 128. Accordingly, the pressure deck 118 is pressurized andserves as a pressure barrier between the pressurized space 106, locatedabove the pressure deck 118, and the non-pressurized space 108, locatedbelow the pressure deck 118.

In an example, the first bulkhead 126 includes a lower portion 232 andan upper portion 182. The lower portion 232 of the first bulkhead 126 iscoupled to the airframe 102 but is not sealed to the airframe 102. Theupper portion 182 of the first bulkhead 126 is coupled to and is sealedto the airframe 102. The pressure deck 118 is coupled to and is sealedto the upper portion 182 of the first bulkhead 126. A portion of thepressure boundary 104 is formed by the sealed connection between theupper portion 182 of the first bulkhead 126 and the airframe 102 (e.g.,the external skin 174 of the airframe 102). A portion of the pressureboundary 104 is formed by the sealed connection between the pressuredeck 118 and the upper portion 182 of the first bulkhead 126.Accordingly, the upper portion 182 of the first bulkhead 126 ispressurized and serves as a pressure barrier between the pressurizedspace 106, located aft of the upper portion 182, and the non-pressurizedspace 108, located forward of upper portion 182. The lower portion 232of the first bulkhead 126 is not pressurized and does not serve as apressure barrier between the non-pressurized space 108, located aft ofthe lower portion 232, and the non-pressurized space 108, locatedforward of the lower portion 232.

In an example, the second bulkhead 128 is coupled to and is sealed tothe airframe 102 and the pressure deck 118. A portion of the pressureboundary 104 is formed by the sealed connection between the secondbulkhead 128 and the airframe 102 (e.g., the external skin 174 of theairframe 102). Accordingly, the second bulkhead 128 is pressurized andserves as a pressure barrier between the pressurized space 106, locatedaft of the second bulkhead 128, and the non-pressurized space 108,located forward of the second bulkhead 128.

In an example, the third bulkhead 132 is coupled to and is sealed to theairframe 102. A portion of the pressure boundary 104 is formed by thesealed connection between the third bulkhead 132 and the airframe 102(e.g., the external skin 174 of the airframe 102). Accordingly, thethird bulkhead 132 is pressurized and serves as a pressure barrierbetween the pressurized space 106, located aft of the second bulkhead128, and the non-pressurized space 108, located forward of the thirdbulkhead 132.

In an example, the nose landing gear box 134 is coupled to and is sealedto the second bulkhead 128, the third bulkhead 132, and the airframe102. A portion of the pressure boundary 104 is formed by the sealedconnection between the nose landing gear box 134 and the second bulkhead128. A portion of the pressure boundary 104 is formed by the sealedconnection between the nose landing gear box 134 and the third bulkhead132. A portion of the pressure boundary 104 is formed by the sealedconnection between the nose landing gear box 134 and the airframe 102(e.g., the external skin 174 of the airframe 102). Accordingly, the noselanding gear box 134 is pressurized and serves as a pressure barrierbetween the pressurized space 106, located outside of the nose landinggear box 134, and the non-pressurized space 108, located inside of thenose landing gear box 134.

In an example, an interior space 258 (FIGS. 10 and 11) of the noselanding gear box 134 (formed between the first sidewall 176, the secondsidewall 178, and the top wall 180) forms a portion of the nose landinggear bay 124 and is located in the non-pressurized space 108. The noselanding gear 136 is coupled to the nose landing gear box 134 within theinterior space 258, as illustrated in FIGS. 3, 4, and 11. A portion ofnose landing gear 136 is stowed within the nose landing gear box 134when the nose landing gear 136 is retracted, as illustrated in FIGS. 4and 12.

In an example, an interior volume 256 (FIGS. 5 and 11) of the aircraft100, located outside of the nose landing gear box 134, between the noselanding gear box 134 and the airframe 102, and between the secondbulkhead 128 and the third bulkhead 132 is in the pressurized space 106.

In an example, the first sidewall 176 of the nose landing gear box 134is coupled to and is sealed to the airframe 102, the second bulkhead128, and the third bulkhead 132. A portion of the pressure boundary 104is formed by the sealed connection between the first sidewall 176 andsecond bulkhead 128. A portion of the pressure boundary 104 is formed bythe sealed connection between the first sidewall 176 and the thirdbulkhead 132. A portion of the pressure boundary 104 is formed by thesealed connection between the first sidewall 176 and the airframe 102(e.g., the external skin 174 of the airframe 102). Accordingly, thefirst sidewall 176 is pressurized and serves as a pressure barrierbetween the pressurized space 106, located outboard of the firstsidewall 176, and the non-pressurized space 108, located inboard of thefirst sidewall 176.

In an example, the second sidewall 178 of the nose landing gear box 134is coupled to and is sealed to the airframe 102, the second bulkhead128, and the third bulkhead 132. A portion of the pressure boundary 104is formed by the sealed connection between the second sidewall 178 andsecond bulkhead 128. A portion of the pressure boundary 104 is formed bythe sealed connection between the second sidewall 178 and the thirdbulkhead 132. A portion of the pressure boundary 104 is formed by thesealed connection between the second sidewall 178 and the airframe 102(e.g., the external skin 174 of the airframe 102). Accordingly, thesecond sidewall 178 is pressurized and serves as a pressure barrierbetween the pressurized space 106, located outboard of the secondsidewall 178, and the non-pressurized space 108, located inboard of thesecond sidewall 178.

In an example, the top wall 180 of the nose landing gear box 134 iscoupled to and is sealed the second bulkhead 128, the third bulkhead132, the first sidewall 176, and the second sidewall 178. A portion ofthe pressure boundary 104 is formed by the sealed connection between thetop wall 180 and second bulkhead 128. A portion of the pressure boundary104 is formed by the sealed connection between the top wall 180 and thethird bulkhead 132. A portion of the pressure boundary 104 is formed bythe sealed connection between the top wall 180 and the first sidewall176. A portion of the pressure boundary 104 is formed by the sealedconnection between the top wall 180 and the second sidewall 178.Accordingly, the top wall 180 is pressurized and serves as a pressurebarrier between the pressurized space 106, located above the top wall180, and the non-pressurized space 108, located below the top wall 180.

Referring to FIGS. 2-4 and 7-14, in an example, the first bulkhead 126is oriented vertically and is coupled to the external skin 174 of theairframe 102 and the pressure deck 118 to form a portion of the pressureboundary 104. In an example, the first bulkhead 126 is coupled to (e.g.,is tied in with) one or more of the frames 172 (FIG. 1) of the airframe102. The first bulkhead 126 is located at a forwardmost position on thewheel well assembly 194.

In an example, the lower portion 232 of the first bulkhead 126 isoriented vertically and extends from the airframe 102 to the pressuredeck 118 and partially delimits the nose landing gear bay 124. In anexample, the pressure deck 118 is coupled to the first bulkhead 126about an intersection of the lower portion 232 and the upper portion182. The upper portion 182 projects from the pressure deck 118.

In an example, the upper portion 182 of the first bulkhead 126 slopesupwardly and forwardly from the pressure deck 118 toward the forward endof the nose structure 160 (e.g., is canted relative to the lower portion232 of the first bulkhead 126). This upward and forward slopedconfiguration of the upper portion 182 of the first bulkhead 126provides improved ability of the first bulkhead 126 to withstand theenergy of an impact with an airborne object, such as a bird strike. Forexample, the angle of the upper portion 182 with respect to a horizontalplane (e.g., the XY-plane) enables the first bulkhead 126 to it deflectthe object downward so that the nose structure 160 receives a glancingblow, thereby not absorbing the entire impact energy. This upward andforward sloped configuration also enables the flight deck 122 (FIG. 3)to sit farther forward, thereby reducing the cross-sectional size of thenose structure 160 and/or shortening a length of the nose structure 160.

In an example, the upper portion 182 of the first bulkhead 126 isdisposed at a non-zero angle with respect to the XY-plane. In anexample, the angle of the upper portion 182 with respect to the XY-planeis approximately forty-five degrees. In another example, the angle ofthe upper portion 182 with respect to the XY-plane is less thanapproximately forty-five degrees.

Referring to FIG. 4, in an example, the nose of the aircraft 100includes a radome 192 that is coupled to the airframe 102 at the forwardend of the aircraft 100. The radome 192 houses certain components of theaircraft 100, such as one or more components of the radar system 224(FIG. 1). In an example, one or more components of the radar system 224,such as at least one antenna 234 (FIGS. 4, 7, and 8) associated with aweather radar system, a glideslope landing system, and/or a localizersystem, are coupled to a forward-facing surface of the lower portion 232of the first bulkhead 126, behind the radome 192. In an example, aninterior volume of the radome 192, forward of the first bulkhead 126 isin the non-pressurized space 108.

Referring to FIGS. 2-4, 6, and 9-11, in an example, the second bulkhead128 is oriented vertically and is coupled to the external skin 174 ofthe airframe 102 and the pressure deck 118 to form a portion of thepressure boundary 104. In an example, the second bulkhead 128 is coupledto (e.g., is tied in with) one or more of the frames 172 (FIG. 1) of theairframe 102. The second bulkhead 128 is located aft of the firstbulkhead 126.

Referring to FIGS. 2-5 and 9-11, in an example, the third bulkhead 132is oriented vertically and is coupled to the external skin 174 of theairframe 102 to form a portion of the pressure boundary 104. In anexample, the third bulkhead 132 is coupled to (e.g., is tied in with)one or more of the frames 172 (FIG. 1) of the airframe 102. The thirdbulkhead 132 is located aft of the second bulkhead 128.

Referring to FIGS. 5, 9-11, and 13, in an example, the first sidewall176 is oriented vertically and is coupled to the external skin 174 ofthe airframe 102 to form a portion of the pressure boundary 104. Thesecond sidewall 178 is oriented vertically and is coupled to theexternal skin 174 of the airframe 102 to form a portion of the pressureboundary 104. In an example, the first sidewall 176 and the secondsidewall 178 are coupled to (e.g., are tied in with) one or more of theframes 172 (FIG. 1) of the airframe 102. In an example, the wheel wellassembly 194 includes frame splices 210 (FIGS. 10 and 11) coupled toeach one of the first sidewall 176 and the second sidewall 178 and tocorresponding ones of the frames 172 (FIG. 2).

Referring generally to FIGS. 3-7, and particularly to FIGS. 10 and 11,in an example, an aft end of each one of the first sidewall 176, thesecond sidewall 178, and the top wall 180 is coupled to the thirdbulkhead 132 and forms a portion of the pressure boundary 104. Thus, thethird bulkhead 132 forms a rear wall, or aft wall, that encloses an aftend of the nose landing gear box 134. A forward end of each one of thefirst sidewall 176, the second sidewall 178, and the top wall 180 iscoupled to the second bulkhead 128 and forms a portion of the pressureboundary 104. The second bulkhead 128 includes an opening 184 (FIGS. 10and 11). The forward ends of the first sidewall 176, the second sidewall178, and the top wall 180 surround a perimeter of the opening 184. Theopening 184 accommodates a portion of the nose landing gear 136 whenretracted into the nose landing gear bay 124.

Referring to FIG. 4, in an example, a portion (e.g., an aft portion) ofthe floor-panel support 110 is supported by the nose landing gear box134. For example, a portion of the floor-panel support 110 is supportedby the top wall 180 of the nose landing gear box 134. In an example, thenose structure 160 includes at least one stanchion 216. The stanchion216 is coupled to the top wall 180 and the floor-panel support 110.

Referring generally to FIGS. 3-7, and particularly to FIGS. 10 and 11,in an example, the nose landing gear box 134 is coupled to the pressuredeck 118. The pressure deck 118 is configured to react to the loadtransmitted by the nose landing gear 136 through the nose landing gearbox 134. For example, the pressure deck 118 transfers the load to theexternal skin 174 and/or the frames 172.

Referring to FIGS. 10 and 11, in an example, the wheel well assembly 194includes gussets 226 coupled to the nose landing gear box 134 and thepressure deck 118. In an example, the gussets 226 extend through theopening 184 of the second bulkhead 128.

Referring generally to FIGS. 2-6 and 9, and particularly to FIGS. 10-12,in an example, the top wall 180 of the nose landing gear box 134 iscoupled to the pressure deck 118. This configuration facilitates a moreeffective load transfer from the nose landing gear box 134 to thepressure deck 118. In an example, the top wall 180 and the pressure deck118 share a common virtual plane 214, as illustrated in FIG. 2.

Referring to FIGS. 2-4, in an example, the pressure deck 118 slopesupwardly from the second bulkhead 128 to the first bulkhead 126 withrespect to a horizontal plane (e.g., the XY-plane). In an example, thetop wall 180 of the nose landing gear box 134 also slopes upwardly fromthe third bulkhead 132 to the second bulkhead 128 (or the pressure deck118) with respect to the horizontal plane (e.g., the XY-plane). Thisupwardly sloping configuration facilitates a reduction in thecross-sectional size, viewed along the central longitudinal axis 188(FIG. 2), of the nose structure 160 and enables the nose landing gear136 to be positioned at a higher relative position, closer to the flightdeck floor 120, when in the retracted position. This upwardly slopingconfiguration also provides a drain path for condensation or otherfluids.

The present disclosure recognizes that in certain types of aircraft,such as freighter or cargo aircraft, it may be desirable for theaircraft to have a less nose down orientation while on the ground, whichin turn orients the floor of the aircraft in a more horizontalorientation and makes moving cargo along the floor in the forward andaft directions easier. One technique for leveling the floor is toincrease the length of the nose landing gear, which raises the nose ofthe aircraft while on the ground. Accordingly, the configuration of thenose structure 160 and, particularly, of the wheel well assembly 194and, more particularly, of the upward slope of the pressure deck 118enables the nose structure 160 to accommodate an increase in the lengthof the nose landing gear 136.

In an example, the pressure deck 118 and/or the top wall 180 of the noselanding gear box 134 is disposed at an acute angle with respect to theXY-plane. In an example, the angle of the pressure deck 118 and/or thetop wall 180 with respect to the XY-plane is less than approximatelyforty-five degrees. In another example, the angle of pressure deck 118and/or the top wall 180 with respect to the XY-plane is less thanapproximately thirty-five degrees. In another example, the angle ofpressure deck 118 and/or the top wall 180 with respect to the XY-planeis less than approximately twenty-five degrees. In another example, theangle of pressure deck 118 and/or the top wall 180 with respect to theXY-plane is less than approximately fifteen degrees.

In another example (not shown in the Figures), the pressure deck 118and/or the top wall 180 of the nose landing gear box 134 is horizontal(e.g., is oriented approximately parallel to the XY-pane).

Accordingly, the wheel well assembly 194 and the airframe 102 form thenose landing gear bay 124 and the pressure boundary 104 delimiting thepressurized space 106 and the non-pressurized space 108. The volume, orspace, within the wheel well assembly 194 is unpressurized (e.g., formsthe non-pressurized space 108). The volume, or space, around the outsideof the wheel well assembly 194 is pressurized (e.g., forms thepressurized space 106).

Referring to FIG. 6, in an example, the nose structure 160 also includesnose landing gear bay doors 228. The nose landing gear bay doors 228 arecoupled to the airframe 102 and are configured to open and close. Whenclosed, the nose landing gear bay doors 228 enclose the nose landinggear bay 124 and form a portion of a bottom of the fuselage 130. In anexample, the nose landing gear bay doors 228 open for deployment andretraction of the nose landing gear 136 and close to stow the noselanding gear 136 within the nose landing gear bay 124 during flight. Inanother example, the nose landing gear bay doors 228 include a forwardset of doors and an aft set of doors. In this example, the forward setof doors are closed when the nose landing gear is fully extended whilethe aft set of doors remain open.

Referring to FIGS. 10 and 11, in an example, the nose structure 160 alsoincludes a pair of forward door beams 212. The forward door beams 212run longitudinally and are coupled to the nose landing gear box 134(e.g., the first sidewall 176 and the second sidewall 178) and to thefirst bulkhead 126. The forward door beams 212 frame out the noselanding gear bay 124. The nose landing gear bay doors 228 (FIG. 6) arecoupled to and supported by the forward door beams 212.

Referring to FIGS. 10, 11, and 13, in an example, the nose structure 160includes a plurality of load reacting members coupled between the wheelwell assembly 194 and the external skin 174 of the airframe 102. In anexample, a first load-reacting member 138 is coupled to the secondbulkhead 128 and to external skin 174. The first load-reacting member138 extends along a boundary between the second bulkhead 128 and theexternal skin 174. The first load-reacting member 138 is configured totransition a load from the second bulkhead 128 to the external skin 174.A second load-reacting member 140 is coupled to the third bulkhead 132and to the external skin 174. The second load-reacting member 140extends along a boundary between the third bulkhead 132 and the externalskin 174. The second load-reacting member 140 is configured totransition a load from the third bulkhead 132 to the external skin 174of the fuselage 130. In an example, the first load-reacting member 138and the second load-reacting member 140 are also coupled to (e.g., tiedin with) corresponding ones of the frame 172 of the airframe 102.

In an example, a third load-reacting member 186 is coupled to the noselanding gear box 134 and to the external skin 174. The thirdload-reacting member 186 extends along a boundary between the firstsidewall 176 and the external skin 174 and between the second sidewall178 and the external skin 174. The third load-reacting member 186 isconfigured to transition a load from the nose landing gear box 134 tothe external skin 174.

Referring generally to FIGS. 1-14, in an example, the disclosed nosestructure 160 of the aircraft 100 includes the airframe 102. Theairframe 102 includes the pressure deck 118 that forms a portion of thepressure boundary 104 delimiting the pressurized space 106 and thenon-pressurized space 108. The nose structure 160 also includes thefloor-panel support 110, supported by the pressure deck 118 in thepressurized space 106. The nose structure 160 further includes aplurality of operational components 248 (FIGS. 5, 6, 8, and 12-14),located in the pressurized space 106 between the floor-panel support 110and the pressure deck 118. The plurality of operational components 248is associated with at least one high-level system 114 of the aircraft100.

In an example, the plurality of operational components 248 includes anynumber of electrical components, mechanical components, hydrauliccomponents, pneumatic components, or other components of the aircraft100 that are used for or are associated with at least one of theelectrical system 150 (FIG. 1), the hydraulic system 152 (FIG. 1), theenvironmental system 154 (FIG. 1), the communication system 156 (FIG.1), the flight control system 222 (FIG. 1), the radar system 224 (FIG.1), or another one of the high-level systems 114 (FIG. 1) of theaircraft 100. In an example, the plurality of operational components 248includes the plurality of transport elements 112 (e.g., communicationlines 148).

In an example, the pressure deck 118 extends from the right side 198 ofthe airframe 102 to the left side 200 of the airframe 102. The pressuredeck 118 and the floor-panel support 110 form a portion of the flightdeck floor 120 of the flight deck 122 of the aircraft 100, located inthe pressurized space 106. The pressure deck 118 forms a portion of thenose landing gear bay 124 of the aircraft 100, located in thenon-pressurized space 108.

In an example, the plurality of operational components 248 is coupled tothe floor-panel support 110 to form the subfloor assembly 208. Thesubfloor assembly 208 is assembled outside of the airframe 102 and iscoupled to the pressure deck 118 inside of the airframe 102.

In an example, the nose structure 160 includes the plurality of floorpanels 116, supported by the floor-panel support 110 and covering theplurality of operational components 248. At least a portion of theplurality of floor panels 116 is removable from the floor-panel support110 to access the plurality of operational components 248 from withinthe flight deck 122.

Referring generally to FIGS. 1-14, also disclosed are examples of theaircraft 100. In an example, the aircraft 100 includes the airframe 102.The airframe 102 forms the nose structure 160 of the aircraft 100. Theaircraft 100 also includes at least one high-level system 114 (FIG. 1).The aircraft 100 further includes the wheel well assembly 194, coupledto the airframe 102 and forming a portion of the nose landing gear bay124. The wheel well assembly 194 includes the pressure deck 118 thatextends from the right side 198 of the airframe 102 to the left side 200of the airframe 102 and that forms a portion of the pressure boundary104 delimiting the pressurized space 106 and the non-pressurized space108. The aircraft 100 also includes the floor-panel support 110,supported by the pressure deck 118. The aircraft 100 further includesthe plurality of transport elements 112, located between the floor-panelsupport 110 and the pressure deck 118. The pressure deck 118 and thefloor-panel support 110 form a portion of the floor 204 of the aircraft100 that delimits the flight deck 122, arranged over the floor 204 inthe pressurized space 106, and the nose landing gear bay 124, arrangedunder the floor 204 in the non-pressurized space 108. The plurality oftransport elements 112 are associated with the at least one high-levelsystem 114. The plurality of transport elements 112 are accessible fromwithin the flight deck 122.

Referring to FIGS. 12-14, in an example of aircraft 100, the pluralityof transport elements 112 is coupled to the floor-panel support 110 toform a subfloor assembly 208. The subfloor assembly 208 is coupled tothe pressure deck 118 within the airframe 102.

In an example, the aircraft 100 includes the plurality of floor panels116, coupled to the floor-panel support 110 and covering the pluralityof transport elements 112. At least a portion of the plurality of floorpanels 116 is removable from the floor-panel support 110 to access theplurality of transport elements 112 from within the flight deck 122.

Referring to FIGS. 8, 9, 13, and 14, in an example of the aircraft 100,the pressure deck 118 includes the platform 144 and the plurality ofsupport beams 146, coupled to the platform 144. The floor-panel support110 is supported by and is coupled to the plurality of support beams146. In an example, each one of the plurality of support beams 146extends longitudinally and is transversely spaced apart from an adjacentone of the plurality of support beams 146. A portion of the plurality oftransport elements 112 is located between the adjacent pair 196 of theplurality of support beams 146.

Referring to FIGS. 9-14, in an example of the aircraft 100, the wheelwell assembly 194 includes a first bulkhead 126, coupled with theairframe 102 running transversely between the right side 198 of theairframe 102 and the left side 200 of the airframe 102. The wheel wellassembly 194 also includes the second bulkhead 128, coupled with the tothe airframe 102 running transversely between the right side 198 of theairframe 102 and the left side 200 of the airframe 102 andlongitudinally spaced away from the first bulkhead 126. The wheel wellassembly 194 further includes the third bulkhead 132, coupled to theairframe 102 running transversely between the right side 198 of theairframe 102 and the left side 200 of the airframe 102 andlongitudinally spaced away from the second bulkhead 128. The wheel wellassembly 194 also includes the nose landing gear box 134, coupled to theairframe 102, the second bulkhead 128, and the third bulkhead 132 andextending between the third bulkhead 132 and the second bulkhead 128.The pressure deck 118 extends between and is coupled to the firstbulkhead 126 and the second bulkhead 128. The first bulkhead 126, thesecond bulkhead 128, the third bulkhead 132, and the nose landing gearbox 134 form a portion of the pressure boundary 104.

Referring to FIGS. 3, 4, 11, and 12, in an example, the aircraft 100includes the nose landing gear 136 coupled to the nose landing gear box134 and stowable within the nose landing gear bay 124.

Referring to FIGS. 3 and 4, in an example, the nose landing gear 136 ismounted within the nose landing gear box 134. The second bulkhead 128and the third bulkhead 132 react to a load transmitted by the noselanding gear 136 through the nose landing gear box 134.

In an example, the aircraft 100 includes an operating mechanism 190 thatis configured to selectively extend (or deploy) the nose landing gear136 from the nose landing gear bay 124 and selectively retract the noselanding gear 136 into the nose landing gear bay 124. In the illustratedexamples, the nose landing gear bay 124 is located at the forward end ofthe fuselage 130 (in the nose structure 160) under the flight deck 122and forms the storage compartment for the nose landing gear 136 when thenose landing gear 136 is retracted.

The operating mechanism 190 of the nose landing gear 136 includesvarious components configured to articulate the nose landing gear 136between the landing and flight positions. As a combined unit, theoperating mechanism 190 and the nose landing gear 136 can withstand theloads and stresses applied during landing, taxiing, towing, and takeoff, as well as other repeated loads and stresses. Additionally, wheelwell assembly 194 (e.g., the nose landing gear box 134, the secondbulkhead 128, and the third bulkhead 132) form a combined structure thatis strong enough to withstand the loads and stresses transmitted by thenose landing gear 136.

Referring to FIGS. 3-6, in an example, the nose landing gear 136includes a trunnion 250, coupled to the nose landing gear box 134. Thenose landing gear 136 also includes a strut 230, coupled to the trunnion250. The nose landing gear 136 further includes an axle 254, coupled tothe strut 230, opposite to the trunnion 250. The nose landing gear 136also includes a wheel 252, coupled to the axle 254. With the noselanding gear 136 stowed within the nose landing gear bay 124, the axle254 is located closer to the central longitudinal axis 188 of theaircraft 100 than the trunnion 250. In other words, with the noselanding gear 136 retracted and stowed within the nose landing gear bay124, the axle 254 is located higher within the aircraft 100 relative tothe trunnion 250 and the nose landing gear 136 is oriented at an upwardangle relative to a horizontal plane.

The strut 230 is articulated so as to be able to pivot between a landingposition, in which the strut 230 is generally vertical to deploy thenose landing gear 136, and a flight position, in which the strut 230 isgenerally horizontal to retract the nose landing gear 136 into the noselanding gear bay 124. As illustrated in FIG. 11, in an example, thestrut 230 is coupled to the first sidewall 176 and the second sidewall178 of the nose landing gear box 134 with the trunnion 250 on eitherside of the nose landing gear box 134. The trunnion 250 provides apivotable connection between the strut 230 and the nose landing gear box134. The nose landing gear 136 may also include an over-center lockinglinkage that is coupled to the nose landing gear box 134 to lock thenose landing gear 136 in the retracted and deployed positions.

Referring to FIGS. 2-4 and 9-14, in an example of the aircraft 100, thepressure deck 118 is coupled to the nose landing gear box 134. In anexample of the aircraft 100, the nose landing gear box 134 includes thefirst sidewall 176, coupled to the airframe 102, the second bulkhead128, and the third bulkhead 132 running longitudinally between the thirdbulkhead 132 and the second bulkhead 128. The nose landing gear box 134also includes the second sidewall 178, coupled to the airframe 102, thesecond bulkhead 128, and the third bulkhead 132 running longitudinallybetween the third bulkhead 132 and the second bulkhead 128. The noselanding gear box 134 further includes the top wall 180, extendingbetween and coupled to the first sidewall 176 and the second sidewall178.

Referring to FIGS. 2-4, in an example of the aircraft 100, the top wall180 and the pressure deck 118 share the common virtual plane 214. In anexample of the aircraft 100, the pressure deck 118 projects upwardlyfrom the second bulkhead 128 to the first bulkhead 126 with respect tothe horizontal plane (e.g., the XY-plane).

Referring to FIGS. 1 and 12-14, in an example of the aircraft 100, theat least one high-level system 114 includes at least one of theelectrical system 150, the hydraulic system 152, the environmentalsystem 154, the communication system 156, the flight control system 222,and the radar system 224 of the aircraft 100. The plurality of transportelements 112 includes at least one communication line 148 for at leastone of the electrical system 150, the hydraulic system 152, theenvironmental system 154, the communication system 156, the flightcontrol system 222, and the radar system 224 of the aircraft 100.

Referring generally to FIGS. 1-14, also disclosed are examples of theairframe 102 of the aircraft 100. In an example, the airframe 102includes the external skin 174. The airframe 102 also includes the firstbulkhead 126, coupled to the external skin 174 running transverselybetween the right side 198 of the airframe 102 and the left side 200 ofthe airframe 102. The airframe 102 further includes the second bulkhead128, longitudinally spaced away from the first bulkhead 126 and coupledto the external skin 174 running transversely between the right side 198of the airframe 102 and the left side 200 of the airframe 102. Theairframe 102 also includes the pressure deck 118, coupled to the firstbulkhead 126, the second bulkhead 128, and the external skin 174 runninglongitudinally between the first bulkhead 126 and the second bulkhead128 and running transversely between the right side 198 of the airframe102 and the left side 200 of the airframe 102. The pressure deck 118,the first bulkhead 126, and the second bulkhead 128 at least partiallydelimit the pressurized space 106 and the non-pressurized space 108 ofthe aircraft 100.

Referring to FIGS. 3 and 4, in an example of the airframe 102, theexternal skin 174, the pressure deck 118, the first bulkhead 126, andthe second bulkhead 128 form at least a portion of a stowage compartment206 of the aircraft 100. The stowage compartment 206 is in thenon-pressurized space 108. In an example, the stowage compartment 206 isthe nose landing gear bay 124 of the aircraft 100.

Referring to FIGS. 2-4, in an example of the airframe 102, the pressuredeck 118 structurally supports at least a portion of the floor 204 ofthe aircraft 100. In an example, the portion of the floor 204 thefloor-panel support 110, supported by the pressure deck 118 in thepressurized space 106. The portion of the floor 204 also includes theplurality of transport elements 112, located between the floor-panelsupport 110 and the pressure deck 118. The portion of the floor 204further includes the plurality of floor panels 116 supported by thefloor-panel support 110 and covering the plurality of transport elements112. The plurality of transport elements 112 are associated with atleast one high-level system 114 of the aircraft 100. At least a portionof the plurality of floor panels 116 is removable from the floor-panelsupport 110 to access the plurality of transport elements 112 fromwithin the pressurized space 106.

Referring to FIGS. 12-14, in an example of the airframe 102, theplurality of transport elements 112 is coupled to the floor-panelsupport 110 to form the subfloor assembly 208. The subfloor assembly 208is assembled outside of the airframe 102, is installed within theairframe 102, and is coupled to the pressure deck 118.

Referring to FIGS. 1-14, also disclosed are examples of the aircraft100. The aircraft 100 includes the fuselage 130 and at least onehigh-level system 114. The aircraft 100 also includes the floor 204. Thefloor 204 includes a pressure deck 118, coupled to the fuselage 130 andforming at least a portion of the pressure boundary 104 delimiting thepressurized space 106 and the non-pressurized space 108. The floor 204further includes the floor-panel support 110, supported by the pressuredeck 118 in the pressurized space 106. The floor 204 also includes theplurality of transport elements 112, located between the floor-panelsupport 110 and the pressure deck 118. The plurality of transportelements 112 being in communication with the at least one high-levelsystem 114 of the aircraft 100.

Referring to FIGS. 12-14, in an example of the aircraft 100, the floor204 includes the plurality of floor panels 116 supported by thefloor-panel support 110 and covering the plurality of transport elements112. At least a portion of the plurality of floor panels 116 isremovable from the floor-panel support 110 to access the plurality oftransport elements 112 from within the pressurized space 106.

In an example of the aircraft 100, the plurality of transport elements112 is coupled to the floor-panel support 110 to form the subfloorassembly 208. The subfloor assembly 208 is assembled outside of thefuselage 130, is installed within the fuselage 130, and is coupled tothe pressure deck 118.

Referring generally to FIGS. 1-4, and particularly to FIGS. 9-11, in anexample, the aircraft 100 includes the first bulkhead 126, coupled tothe fuselage 130 transverse to a central longitudinal axis 188 of thefuselage 130 and forming at least a portion of the pressure boundary104. The aircraft 100 also includes the second bulkhead 128, coupled tothe fuselage 130 transverse to the central longitudinal axis 188 of thefuselage 130 and forming at least a portion of the pressure boundary104. The first bulkhead 126 and the second bulkhead 128 are spaced apartfrom each other along the central longitudinal axis 188 of the fuselage130. The pressure deck 118 extends between and is coupled to the firstbulkhead 126 and the second bulkhead 128.

Referring generally to FIGS. 1-14, in an example, the aircraft 100includes the airframe 102 and the wheel well assembly 194, coupled tothe airframe 102. The wheel well assembly 194 and the airframe 102 formthe nose landing gear bay 124. The aircraft 100 also includes the noselanding gear 136, stowable within the nose landing gear bay 124. Thenose landing gear 136 includes the trunnion 250, coupled to the wheelwell assembly 194. The nose landing gear 136 also includes the strut230, coupled to the trunnion 250. The nose landing gear 136 furtherincludes the axle 254, coupled to the strut 230, opposite to thetrunnion 250. The nose landing gear 136 also includes the wheel 252,coupled to the axle 254. With the nose landing gear 136 stowed withinthe nose landing gear bay 124, the axle 254 is located closer to acentral longitudinal axis 188 of the aircraft 100 than the trunnion 250.

In an example, the wheel well assembly 194 and the airframe 102 delimitthe pressurized space 106 and the non-pressurized space 108 of theaircraft 100. The nose landing gear bay 124 is located in thenon-pressurized space 108.

In an example, the wheel well assembly 194 includes the pressure deck118, coupled to the airframe 102. The pressure deck 118 extends from theright side 198 of the airframe 102 to the left side 200 of the airframe102 and slopes upwardly with respect to a horizontal plane in a forwarddirection. The wheel well assembly 194 also includes the nose landinggear box 134, coupled to the pressure deck 118 and the airframe 102. Thenose landing gear box 134 extends from the pressure deck 118 in arearward direction. The trunnion 250 of the nose landing gear 136 iscoupled to the nose landing gear box 134. With the nose landing gear 136stowed within the nose landing gear bay 124, the wheel 252 of the noselanding gear 136 is located adjacent to the pressure deck 118.

In an example, the aircraft 100 includes the floor-panel support 110,coupled to the pressure deck 118 in the pressurized space 106. Thepressure deck 118 and the floor-panel support 110 form a portion of theflight deck floor 120 of the flight deck 122 of the aircraft 100. Theaircraft 100 also includes the plurality of operational components 248,located between the floor-panel support 110 and the pressure deck 118.

Accordingly, the examples of the nose structure 160, the airframe 102,and the aircraft 100 described herein combine, or integrate, the wheelwell assembly 194, forming the nose landing gear bay 124 and delimitingthe pressure boundary 104, and the floor-panel support 110 to form thefloor 204 of the fuselage 130 and, more particularly, the flight deckfloor 120 between the flight deck 122 and the nose landing gear bay 124.Further, the examples of the nose structure 160, the airframe 102, andthe aircraft 100 described herein locate at least a portion of theplurality of transport elements 112 within the flight deck floor 120,between the floor-panel support 110 and the wheel well assembly 194.This configuration of the nose structure 160, the airframe 102, and theaircraft 100 reduces the overall volume required by the forward portionof the fuselage 130 to accommodate the nose landing gear 136 (in theretracted, flight position) and the plurality of transport elements 112.

This configuration also provides a unique geometry for the nosestructure 160 and, more particularly, the loft shape of the nosestructure 160. Loft shapes of the nose structure of the fuselage aretypically described in terms of length divided by diameter (LID). TheLID is directly related to the aerodynamic performance of the aircraft,particularly as speed increases. Generally, it is desirable that theloft shape be as circular as possible. The examples of the nosestructure 160, the airframe 102, and the aircraft 100 described hereinenables an increase in the rate of change of a loft angle 142 (FIG. 2)and a reduction in the overall surface area (wetted area) of the nosestructure 160 of the fuselage 130.

As an example, the cross-sectional size of the nose structure 160 isreduced compared to traditional fuselage design. As another example, theloft angle 142 of a loft surface 236 (FIG. 2) of the nose structure 160,extending from a keel 238 (FIG. 2) of the fuselage 130 to the tip 218 ofthe nose of the fuselage 130, has a faster rate of change. In theillustrative examples, the loft angle 142 of the nose structure 160changes from about zero degrees at the keel 238 of the fuselage 130 toabout ninety degrees at the tip 218 of the nose over a shorterlongitudinal distance compared to traditional fuselage design.Additionally, the configurations disclosed herein enables the tip 218 ofthe nose structure 160 (e.g., the farthest point forward of the fuselage130) to be located at a closer linear distance to the centrallongitudinal axis 188 (extending through a centroid of the cylindricalbarrel section 246 of the fuselage 130 of the aircraft 100) (FIG. 1),which essentially lifts the nose of the fuselage 130 and reduces drag onthe aircraft 100 compared to traditional fuselage design.

Furthermore, combining, or integrating, the floor-panel support 110 andthe plurality of transport elements 112 enables the plurality oftransport elements 112 to be laid out on the floor-panel support 110prior to installation of the subfloor assembly 208 within the aircraft100. In this way, large components of the aircraft 100 can be builtoutside of the airframe 102 and then installed, which reducesmanufacturing time and cost. The disclosed configuration also enablesthe plurality of transport elements 112 to be in the pressurized space106, within the flight deck floor 120 and under the flight deck 122. Inthis way, the transport elements 112 remain easily accessible, bothduring flight and when the aircraft 100 is on the ground, compared tothe limited space provided for this area in traditional fuselage designthat is extremely difficult to access during installation, maintenance,and/or inspection of the various systems located in this area.

In various examples, the components of the disclosed nose structure 160,airframe 102, and aircraft 100 may be made of any suitable materials. Inan example, the floor-panel support 110 is made of aluminum. In anexample, the pressure deck 118 is made of a composite. In an example,the first bulkhead 126 is made of aluminum. In an example, the secondbulkhead 128 is made of a composite. In an example, the third bulkhead132 is made of aluminum. In an example, the first load-reacting member138, the second load-reacting member 140, and the third load-reactingmember 186 (e.g., the chords) are made of titanium.

In another example, the floor-panel support 110 is made of a composite.Using aluminum over composite for the floor-panel support 110 providesan additional benefit in electrical current return networks and is lesscostly than composite. Using composite over aluminum provides reducedoverall weight.

In another example, the pressure deck 118 and the second bulkhead 128are made of aluminum. Composites may be selected for the pressure deck118 and the second bulkhead 128 for maintenance considerations andweight, as well as coefficient of thermal similarity to the externalskin 174 of the fuselage 130, for example, when the external skin 174 ismade of a composite.

In another example, the first bulkhead 126 and the third bulkhead 132are made of a composite. Aluminum may be selected for the first bulkhead126 due to its ability to absorb the energy of a bird impact. Forexample, a first bulkhead 126 made of aluminum may be more likely toabsorb an impact and deform as opposed to a first bulkhead 126 made ofcomposite, which may have less damage tolerance. Aluminum may beselected for the third bulkhead 132 due to the large amounts oflocalized high loading around the nose landing gear box 134.

In another example, one or more of the first load-reacting member 138,the second load-reacting member 140, and the third load-reacting member186 are made of a composite. Titanium may be selected for the firstload-reacting member 138, the second load-reacting member 140, and thethird load-reacting member 186 due to its high strength to weightratios, fatigue performance, coefficient of thermal contraction, and thecorrosion isolation it provides between aluminum and compositestructure.

FIG. 15 is a flow diagram of an example of a method 1000. In someexamples, the method 1000 is applicable to making the aircraft 100described herein. In some examples, the method 1000 is similarlyapplicable to making the nose structure 160 and/or the airframe 102described herein.

Referring generally to FIGS. 1-14 and particularly to FIG. 15, in anexample, the method 1000 includes a step of (block 1002) assembling thesubfloor assembly 208. The subfloor assembly 208 includes thefloor-panel support 110 and the plurality of transport elements 112. Themethod 1000 also includes a step of (block 1006) coupling the wheel wellassembly 194 to the airframe 102 of the aircraft 100 to form the noselanding gear bay 124 of the aircraft 100. The method 1000 also includesa step of (block 1012) coupling the subfloor assembly 208 to the wheelwell assembly 194, in the pressurized space 106, to form a portion ofthe floor 204 (e.g., the flight deck floor 120) of the aircraft 100 sothat the plurality of transport elements 112 is located between thefloor-panel support 110 and the wheel well assembly 194.

In an example, the method 1000 further includes a step of (block 1016)coupling the plurality of transport elements 112 to the at least onehigh-level system 114 of the aircraft 100.

In an example, the method 1000 includes a step of (block 1010) formingthe pressure boundary 104 delimiting the pressurized space 106 and thenon-pressurized space 108 with the wheel well assembly 194 and theairframe 102.

In an example, according to the method 1000, the step of (block 1002)assembling the subfloor assembly 208 includes a step of coupling theplurality of transport elements 112 and the floor-panel support 110together outside of the airframe 102. The step of (block 1012) couplingthe subfloor assembly 208 to the wheel well assembly 194 includes a stepof (block 1014) installing the subfloor assembly 208 within the airframe102. In an example, the step of (block 1012) coupling the subfloorassembly 208 to the wheel well assembly 194 includes a step of couplingthe floor-panel support 110 to the pressure deck 118.

In an example, the method 1000 includes a step of (block 1018) couplingthe plurality of floor panels 116 to the floor-panel support 110. Theplurality of floor panels 116 form a portion of the floor 204 (e.g., theflight deck floor 120) and cover the plurality of transport elements112. At least a portion of the plurality of floor panels 116 isremovable from the floor-panel support 110 to access the plurality oftransport elements 112 from within the pressurized space 106.

In an example, the method 1000 includes a step of (block 1004)assembling the wheel well assembly 194. The wheel well assembly 194includes the pressure deck 118. The wheel well assembly 194 alsoincludes the first bulkhead 126, coupled to the pressure deck 118. Thewheel well assembly 194 further includes the second bulkhead 128,coupled to the pressure deck 118, longitudinally spaced away from thefirst bulkhead 126. The wheel well assembly 194 also includes the noselanding gear box 134, coupled to the second bulkhead 128, opposite tothe first bulkhead 126. The wheel well assembly 194 further includes thethird bulkhead 132, coupled to the nose landing gear box 134, oppositeto the second bulkhead 128.

In an example, according to the method 1000, the step of (block 1004)assembling the wheel well assembly 194 includes a step of coupling thepressure deck 118, the first bulkhead 126, the second bulkhead 128, thenose landing gear box 134, and the third bulkhead 132 together outsideof the airframe 102. The step of (block 1006) coupling the wheel wellassembly 194 to the airframe 102 includes a step of (block 1008)installing the wheel well assembly 194 within the airframe 102.

In an example, according to the method 1000, the nose landing gear box134 includes the first sidewall 176, extending between and coupled tothe third bulkhead 132 and the second bulkhead 128. The nose landinggear box 134 also includes the second sidewall 178, extending betweenand coupled to the third bulkhead 132 and the second bulkhead 128. Thenose landing gear box 134 further includes the top wall 180, extendingbetween and coupled to the first sidewall 176, the second sidewall 178,the third bulkhead 132, and the second bulkhead 128. The step of (block1004) assembling the wheel well assembly 194 includes a step of couplingthe top wall 180 of the nose landing gear box 134 and the pressure deck118 together such that the top wall 180 and the pressure deck 118 sharethe common virtual plane 214.

In an example, the step of (block 1004) assembling the wheel wellassembly 194 includes a step of sloping the pressure deck 118 upwardlyfrom the second bulkhead 128 to the first bulkhead 126 with respect tothe horizontal plane (e.g., the XY-plane).

In an example, according to the method 1000, the wheel well assembly 194includes the plurality of support beams 146, configured to support thefloor-panel support 110. Each one of the plurality of support beams 146is spaced apart from an adjacent one of the plurality of support beams146. The step of (block 1012) coupling the subfloor assembly 208 to thewheel well assembly 194 includes a step of locating a portion of theplurality of transport elements 112 between the adjacent pair 196 of theplurality of support beams 146.

In an example, the method 1000 includes a step of (block 1020) couplingthe nose landing gear 136 to the wheel well assembly 194 within the noselanding gear bay 124.

In an example, according to the method 1000, the step of forming thepressure boundary 104 includes steps of: sealingly coupling the pressuredeck 118 with the airframe 102 to form a portion of the pressureboundary 104; sealingly coupling the first bulkhead 126 with thepressure deck 118 and the airframe 102 to form a portion of the pressureboundary 104; sealingly coupling the second bulkhead 128 with thepressure deck 118 and the airframe 102 to form a portion of the pressureboundary 104; sealingly coupling the nose landing gear box 134 with thesecond bulkhead 128 and the airframe 102 to form a portion of thepressure boundary 104; and sealingly coupling the third bulkhead 132with the nose landing gear box 134 and the airframe 102 to form aportion of the pressure boundary 104.

In an example, according to the method 1000, the second bulkhead 128 andthe third bulkhead 132 react to the load transmitted by the nose landinggear 136 through the nose landing gear box 134. In an example, themethod 1000 also includes a steps of coupling the first load-reactingmember 138 to the second bulkhead 128 and to the external skin 174 ofthe airframe 102 and a step of coupling the second load-reacting member140 to the third bulkhead 132 and to the external skin 174 of theairframe 102. The first load-reacting member 138 reacts to a loadtransmitted by the nose landing gear 136 through the second bulkhead128. The second load-reacting member 140 reacts to a load transmitted bythe nose landing gear 136 through the third bulkhead 132. The method1000 may also include a step of coupling the third load-reacting member186 to the nose landing gear box 134 and to the external skin 174 of theairframe 102.

FIG. 16 is a flow diagram of an example of a method 2000. In someexamples, the method 2000 is applicable to making the aircraft 100described herein. In some examples, the method 2000 is similarlyapplicable to making the nose structure 160 and/or the airframe 102described herein.

Referring generally to FIGS. 1-14 and particularly to FIG. 16, in anexample, the method 2000 includes a step of (block 2002) coupling thewheel well assembly 194 to the airframe 102 of the aircraft 100. Themethod 2000 also includes a step of (block 2008) forming the noselanding gear bay 124 with the wheel well assembly 194 and the airframe102. The method 2000 further includes a step of (block 2020) couplingthe nose landing gear 136 to the wheel well assembly 194. The method2000 also includes a step of (block 2024) stowing the nose landing gear136 within the nose landing gear bay 124 so that an axle 254 of the noselanding gear 136 is located closer to a central longitudinal axis 188 ofthe aircraft 100 than a trunnion 250 of the nose landing gear 136.

In an example, the method 2000 includes a step of (block 2010) formingthe pressure boundary 104 that delimits the pressurized space 106 andthe non-pressurized space 108 with the wheel well assembly 194 and theairframe 102. The nose landing gear bay 124 is located in thenon-pressurized space 108.

In an example, according to the method 2000, the step of (block 2002)coupling the wheel well assembly 194 to the airframe 102 of the aircraft100 comprises a step of (block 2004) coupling the pressure deck 118 ofthe wheel well assembly 194 to the airframe 102. The pressure deck 118extends from the right side 198 of the airframe 102 to the left side 200of the airframe 102 and slopes upwardly with respect to a horizontalplane in a forward direction.

In an example, the method 2000 includes a step of (block 2012) couplingthe plurality of operational components 248 of the aircraft 100 to thefloor-panel support 110. The method 2000 also includes a step of (block2014) coupling the floor-panel support 110 to the pressure deck 118 sothat the plurality of operational components 248 is located in thepressurized space 106 between the floor-panel support 110 and thepressure deck 118. The method 2000 further includes a step of (block2016) coupling the plurality of floor panels 116 to the floor-panelsupport 110 to cover the plurality of operational components 248.

In an example, the method 2000 includes a step of (block 2018) accessingthe plurality of operational components 248 by removing at least aportion of the plurality of floor panels 116.

In an example, according to the method 2000, the step of (block 2002)coupling the wheel well assembly 194 to the airframe 102 of the aircraft100 includes a step of (block 2006) coupling the nose landing gear box134 to the airframe 102 and to the pressure deck 118. The nose landinggear box 134 extends from the pressure deck 118 in a rearward direction.The step of (block 2020) coupling the nose landing gear 136 to the wheelwell assembly 194 includes a step of (block 2022) coupling the trunnion250 to the nose landing gear box 134.

In an example, according to the method 2000, the step of (block 2002)coupling the wheel well assembly 194 to the airframe 102 of the aircraft100 includes a step of coupling the first bulkhead 126 to the pressuredeck 118 and to the airframe 102. The first bulkhead 126 runstransversely between the right side 198 of the airframe 102 and the leftside 200 of the airframe 102. The step of (block 2002) coupling thewheel well assembly 194 to the airframe 102 of the aircraft 100 alsoincludes a step of coupling the second bulkhead 128 to the nose landinggear box 134 and to the airframe 102. The second bulkhead 128 runstransversely between the right side 198 of the airframe 102 and the leftside 200 of the airframe 102 and is longitudinally spaces away from thefirst bulkhead 126. The step of (block 2002) coupling the wheel wellassembly 194 to the airframe 102 of the aircraft 100 further includes astep of coupling the third bulkhead 132 to the nose landing gear box134, opposite to the second bulkhead 128, and to the airframe 102. Thethird bulkhead 132 runs transversely between the right side 198 of theairframe 102 and the left side 200 of the airframe 102. The pressuredeck 118 slopes upwardly with respect to the horizontal plane from thesecond bulkhead 128 to the first bulkhead 126.

FIG. 17 is a flow diagram of an example of a method 3000. In someexamples, the method 3000 is applicable to making the aircraft 100described herein. In some examples, the method 3000 is similarlyapplicable to making the nose structure 160 and/or the airframe 102described herein.

Referring generally to FIGS. 1-14 and particularly to FIG. 17, in anexample, the method 3000 includes a step of (block 3002) coupling thepressure deck 118 to the airframe 102 of the aircraft 100. The pressuredeck 118 extends from the right side 198 of the airframe 102 to the leftside 200 of the airframe 102. The method 3000 also includes a step of(block 3004) coupling the nose landing gear box 134 to the pressure deck118 and to the airframe 102. The nose landing gear box 134 is locatedrearward of the pressure deck 118. The method 3000 further includes astep of (block 3006) forming a portion of the pressure boundary 104 thatdelimits the pressurized space 106 and the non-pressurized space 108 ofthe aircraft 100 with the pressure deck 118, the nose landing gear box134, and the airframe 102. The method 3000 also includes a step of(block 3008) forming a portion of the nose landing gear bay 124 of theaircraft 100, located in the non-pressurized space 108, with thepressure deck 118, the nose landing gear box 134, and the airframe 102.The nose landing gear box 134 extends longitudinally in a forwarddirection and forms a portion of the nose landing gear bay 124 but doesnot extend the entire length of the nose landing gear bay 124. Themethod 3000 further includes a step of (block 3012) coupling thefloor-panel support 110 to the pressure deck 118 and to the nose landinggear box 134 in the pressurized space 106 to form the flight deck floor120 of the flight deck 122 above the nose landing gear bay 124. Themethod 3000 also includes a step of (block 3014) accessing the interiorvolume 256 of the aircraft 100, located between the nose landing gearbox 134 and the airframe 102, from within the flight deck 122 throughthe floor-panel support 110.

In an example, the method 3000 includes a step of (block 3018) couplingthe nose landing gear 136 of the aircraft 100 to the nose landing gearbox 134 so that the nose landing gear 136 is stowable within the noselanding gear bay 124 below the pressure deck 118.

In an example, the method 3000 includes a step of (block 3010) couplingthe plurality of transport elements 112, associated with the at leastone high-level system 114 of the aircraft 100, to the floor-panelsupport 110 before the step of (block 3012) coupling the floor-panelsupport 110 to the pressure deck 118 and the nose landing gear box 134so that the plurality of transport elements 112 is located between thefloor-panel support 110 and the pressure deck 118 and between thefloor-panel support 110 and the nose landing gear box 134. The method3000 also includes a step of (block 3016) accessing the plurality oftransport elements 112 from within the flight deck 122 through thefloor-panel support 110.

FIG. 18 is a flow diagram of an example of a method 4000 of accessing aportion of the aircraft 100. In some examples, the method 4000 isapplicable to assembling the portion of the aircraft 100. In someexamples, the method 4000 is applicable to inspecting the portion of theaircraft 100. In some examples, the method 4000 is applicable toperforming maintenance on the portion of the aircraft 100.

Referring generally to FIGS. 1-14 and particularly to FIG. 18, in anexample, the method 4000 includes a step of (block 4002) entering theinterior volume 256 of the aircraft 100 through the floor-panel support110. In an example, according to the method 4000, the interior volume256 is formed by the airframe 102, the wheel well assembly (194),coupled to the airframe (102), and the floor-panel support (110),coupled to the wheel well assembly (194). The method (4000) alsoincludes a step of (block 4004) accessing at least a portion of thewheel well assembly 194 from within the interior volume 256. Inaccordance with the method 4000, the interior volume 256 and thecomponents of the wheel well assembly 194 (e.g., the first bulkhead 126,the second bulkhead 128, the third bulkhead 132, the nose landing gearbox 134, and the pressure deck 118) and the airframe 102 are accessiblethrough the floor-panel support 110 from within the flight deck 122.

The present disclosure recognizes and takes into account that in certainaircraft designs, a wheel well structure and an interior volume betweenthe wheel well structure and an airframe is accessed through openings inlongitudinal bulkheads forming the wheel well structure, which areentered through a nose landing gear bay. This means of entry isdifficult and uncomfortable for an operator. The configuration of thenose structure 160 and methods disclosed herein advantageously reducethe difficulty for an operator accessing the wheel well assembly 194,such as during assembly, inspection, and/or maintenance, by providingaccess to the wheel well assembly 194 through the floor-panel support110 from within the flight deck 122.

The present disclosure also recognizes and takes into account that incertain aircraft designs, the longitudinal bulkheads forming the wheelwell structure extend the entire length of a nose landing gear bay of anaircraft. In such a design, the interior volume formed between thelongitudinal bulkheads and an airframe is very small toward the frontend of the aircraft, making access difficult. The configuration of thenose structure 160 and methods disclosed herein advantageously easeaccess by having the longitudinal components of the wheel well assembly194 (e.g., the nose landing gear box 134) extend only a portion of thenose landing gear bay 124.

In an example, the method 4000 includes a step of (block 4006) accessingat least a portion of the plurality of transport elements 112, locatingbetween the floor-panel support 110 and the wheel well assembly 194,through the floor-panel support 110. In accordance with the method 4000,the plurality of transport elements 112 and/or the plurality ofoperational components 248 are accessible through the floor-panelsupport 110 from within the flight deck 122.

The present disclosure recognizes and takes into account that in certainaircraft designs, operational components and/or transport elementsassociated with high-level system of an aircraft are typically locatedwithin an interior volume formed between the longitudinal bulkheadsforming the wheel well structure and an airframe. In such a design,access to these components is difficult for an operator. Theconfiguration of the nose structure 160 and methods disclosed hereinadvantageously reduces the difficulty for an operator accessing theplurality of transport elements 112 and/or the plurality of operationalcomponents 248, such as during assembly, inspection, and/or maintenanceby providing access to the plurality of transport elements 112 and/orthe plurality of operational components 248 through the floor-panelsupport 110 from within the flight deck 122.

Referring now to FIG. 19, examples of the nose structure 160, theairframe 102, the aircraft 100, and methods 1000, 2000, 3000, 4000 maybe used in the context of an aircraft manufacturing and service method1100, as shown in the flow diagram of FIG. 19. Aircraft applications mayinclude manufacturing and servicing the aircraft 100 that includes theconfigurations of the nose structure 160 and the airframe 102 disclosedherein.

As illustrated in FIG. 19, during pre-production, the method 1100 mayinclude specification and design of aircraft 100 (block 1102) andmaterial procurement (block 1104). During production of the aircraft100, component and subassembly manufacturing (block 1106) and systemintegration (block 1108) of the aircraft 100 may take place. Thereafter,the aircraft 100 may go through certification and delivery (block 1110)to be placed in service (block 1112). Implementation of the disclosednose structure 160, airframe 102, and method 1000 may form a portion ofcomponent and subassembly manufacturing (block 1106) and/or systemintegration (block 1108). Routine maintenance and service (block 1114)may include modification, reconfiguration, refurbishment, etc. of one ormore systems of the aircraft 100.

Each of the processes of the method 1100 illustrated in FIG. 19 may beperformed or carried out by a system integrator, a third party, and/oran operator (e.g., a customer). For the purposes of this description, asystem integrator may include, without limitation, any number ofaircraft manufacturers and major-system subcontractors; a third partymay include, without limitation, any number of vendors, subcontractors,and suppliers; and an operator may be an airline, leasing company,military entity, service organization, and so on.

Examples of the nose structure 160, the airframe 102, the aircraft 100,and the methods 1000, 2000, 3000, 4000 shown or described herein may beemployed during any one or more of the stages of the aircraftmanufacturing and service method 1100, shown in the flow diagramillustrated by FIG. 18. For example, assembly and installation of thesubfloor assembly 208 and the wheel well assembly 194 may correspond tocomponent and subassembly manufacturing (block 1106) and may be preparedin a manner similar to components or subassemblies prepared while theaircraft 100 is in service (block 1112). Also, one or more examples ofthe nose structure 160, the airframe 102, the aircraft 100, and themethods 1000, 2000, 3000, 4000 described herein may be utilized duringsystem integration (block 1108) and certification and delivery (block1110). Similarly, one or more examples of the nose structure 160, theairframe 102, the aircraft 100, and the methods 1000, 2000, 3000, 4000described herein may be utilized, for example and without limitation,while the aircraft 100 is in service (block 1112) and during maintenanceand service (block 1114).

Although an aerospace example is shown, the examples and principlesdisclosed herein may be applied to other industries, such as theautomotive industry, the space industry, the construction industry, andother design and manufacturing industries. Accordingly, in addition toaircraft, the examples and principles disclosed herein may apply toother vehicle structures (e.g., land vehicles, marine vehicles, spacevehicles, etc.) and stand-alone structures where structures are requiredto delimit a pressurized space and a non-pressurized space and areduction in overall volume is beneficial.

As used herein, a system, apparatus, device, structure, article,element, component, or hardware “configured to” perform a specifiedfunction is indeed capable of performing the specified function withoutany alteration, rather than merely having potential to perform thespecified function after further modification. In other words, thesystem, apparatus, device, structure, article, element, component, orhardware “configured to” perform a specified function is specificallyselected, created, implemented, utilized, programmed, and/or designedfor the purpose of performing the specified function. As used herein,“configured to” denotes existing characteristics of a system, apparatus,structure, article, element, component, or hardware that enable thesystem, apparatus, structure, article, element, component, or hardwareto perform the specified function without further modification. Forpurposes of this disclosure, a system, apparatus, device, structure,article, element, component, or hardware described as being “configuredto” perform a particular function may additionally or alternatively bedescribed as being “adapted to” and/or as being “operative to” performthat function.

For the purpose of this disclosure, the terms “coupled,” “coupling,” andsimilar terms refer to two or more elements that are joined, linked,fastened, attached, connected, integrally formed, put in communication,or otherwise associated (e.g., mechanically, electrically, fluidly,optically, electromagnetically) with one another. In various examples,the elements may be associated directly or indirectly. As an example,element A may be directly associated with element B. As another example,element A may be indirectly associated with element B, for example, viaanother element C. It will be understood that not all associations amongthe various disclosed elements are necessarily represented. Accordingly,couplings other than those depicted in the figures may also exist.

FIGS. 1-14, referred to above, schematically illustrate examples of thedisclosed nose structure 160, airframe 102 and aircraft 100 and do notnecessarily imply any particular structure. Accordingly, modifications,additions and/or omissions may be made to the illustrated structure.Additionally, those skilled in the art will appreciate that not allelements described and illustrated in FIGS. 1-14, referred to above,need be included in every example and not all elements described hereinare necessarily depicted in each illustrative example. Unless otherwiseexplicitly stated, the schematic illustrations of examples depicted inFIGS. 1-14, referred to above, are not meant to imply structurallimitations with respect to the illustrative example. Rather, althoughone illustrative structure is indicated, it is to be understood that thestructure may be modified when appropriate.

In FIGS. 15-19, referred to above, the blocks may represent operations,steps, and/or portions thereof and lines connecting the various blocksdo not imply any particular order or dependency of the operations orportions thereof. It will be understood that not all dependencies amongthe various disclosed operations are necessarily represented. FIGS.15-19 and the accompanying disclosure describing the operations of thedisclosed methods set forth herein should not be interpreted asnecessarily determining a sequence in which the operations are to beperformed. Rather, although one illustrative order is indicated, it isto be understood that the sequence of the operations may be modifiedwhen appropriate. Accordingly, modifications, additions and/or omissionsmay be made to the operations illustrated and certain operations may beperformed in a different order or simultaneously. Additionally, thoseskilled in the art will appreciate that not all operations describedneed be performed.

Further, references throughout the present specification to features,advantages, or similar language used herein do not imply that all of thefeatures and advantages that may be realized with the examples disclosedherein should be, or are in, any single example. Rather, languagereferring to the features and advantages is understood to mean that aspecific feature, advantage, or characteristic described in connectionwith an example is included in at least one example. Thus, discussion offeatures, advantages, and similar language used throughout the presentdisclosure may, but do not necessarily, refer to the same example.

The described features, advantages, and characteristics of one examplemay be combined in any suitable manner in one or more other examples.One skilled in the relevant art will recognize that the examplesdescribed herein may be practiced without one or more of the specificfeatures or advantages of a particular example. In other instances,additional features and advantages may be recognized in certain examplesthat may not be present in all examples. Furthermore, although variousexamples of the nose structure 160, the airframe 102, the aircraft 100,and the method 1000 have been shown and described, modifications mayoccur to those skilled in the art upon reading the specification. Thepresent application includes such modifications and is limited only bythe scope of the claims.

Referring to FIGS. 20-26, also disclosed is an ornamental design for anose section of an aircraft. The broken lines shown in FIGS. 20-26 arefor illustrative purposes only and form no part of the disclosed design.

What is claimed is:
 1. A nose structure of an aircraft, the nosestructure comprising: an airframe; and a wheel well assembly, coupled tothe airframe and forming a portion of a nose landing gear bay, the wheelwell assembly comprising a pressure deck that extends from a right sideof the airframe to a left side of the airframe and a nose landing gearbox that is coupled to the pressure deck; a floor-panel support,supported by the pressure deck; a plurality of floor panels, coupled tothe floor-panel support; and a plurality of transport elements, coupledto the floor-panel support between the floor-panel support and thepressure deck, wherein: the pressure deck and the nose landing gear boxform a portion of a pressure boundary delimiting a pressurized space anda non-pressurized space; the plurality of transport elements is locatedin the pressurized space and is couplable to at least one of anelectrical system, a hydraulic system, an environmental system, acommunications system, a propulsion system, a flight control system, anda radar system of the aircraft; and the plurality of transport elementsis accessible from within the pressurized space through the floor-panelsupport.
 2. The nose structure of claim 1, wherein the pressure deck,the floor-panel support, and the plurality of floor panels form aportion of a floor of the aircraft that delimits a flight deck of theaircraft, arranged over the floor in the pressurized space, and the noselanding gear bay, arranged under the floor in the non-pressurized space.3. The nose structure of claim 1, wherein: the plurality of transportelements and the floor-panel support form a pre-assembled subfloorassembly; and the pre-assembled subfloor assembly is coupled to thepressure deck within the airframe.
 4. The nose structure of claim 1,wherein: at least a portion of the plurality of floor panels, cover atleast a portion of the plurality of transport elements; and at least theportion of the plurality of floor panels is removable from thefloor-panel support to access at least the portion of the plurality oftransport elements.
 5. The nose structure of claim 1, wherein: thepressure deck comprises: a platform; and a plurality of support beams,coupled to the platform, each one of the plurality of support beamsextends longitudinally and is transversely spaced apart from an adjacentone of the plurality of support beams; the floor-panel support issupported by and is coupled to the plurality of support beams; and aportion of the plurality of transport elements is located between anadjacent pair of the plurality of support beams.
 6. The nose structureof claim 1, wherein: the wheel well assembly further comprises: a firstbulkhead, coupled to the airframe running transversely between the rightside of the airframe and the left side of the airframe and forming aportion of the pressure boundary; and a second bulkhead, coupled to theairframe running transversely between the right side of the airframe andthe left side of the airframe and forming a portion of the pressureboundary; the first bulkhead and the second bulkhead are longitudinallyspaced apart from each other; and the pressure deck extends between andis coupled to the first bulkhead and the second bulkhead.
 7. The nosestructure of claim 6, wherein: the nose landing gear box is coupled tothe second bulkhead and to the airframe; a nose landing gear of theaircraft is mountable within the nose landing gear box and is stowablewithin the nose landing gear bay; and the second bulkhead is configuredto react to a load transmitted by the nose landing gear through the noselanding gear box.
 8. The nose structure of claim 7, wherein: the wheelwell assembly further comprises a third bulkhead, coupled to theairframe running transversely between the right side of the airframe andthe left side of the airframe, longitudinally spaced away from thesecond bulkhead, and forming a portion of the pressure boundary; thenose landing gear box is further coupled to the third bulkhead andextends between the second bulkhead and the third bulkhead; and thethird bulkhead is configured to react to the load transmitted by thenose landing gear through the nose landing gear box.
 9. The nosestructure of claim 8, wherein the nose landing gear box comprises: afirst sidewall, coupled to the airframe, the second bulkhead, and thethird bulkhead running longitudinally between the third bulkhead and thesecond bulkhead and forming a portion of the pressure boundary; a secondsidewall, coupled to the airframe, the second bulkhead, and the thirdbulkhead running longitudinally between the third bulkhead and thesecond bulkhead and forming a portion of the pressure boundary; and atop wall, extending between and coupled to the first sidewall, thesecond sidewall, the third bulkhead, and the second bulkhead and forminga portion of the pressure boundary.
 10. The nose structure of claim 9,wherein: the top wall of the nose landing gear box is coupled to thepressure deck; the top wall and the pressure deck share a virtual plane;and the pressure deck is configured to react to the load transmitted bythe nose landing gear through the nose landing gear box.
 11. The nosestructure of claim 10, wherein the pressure deck slopes upwardly andforwardly from the second bulkhead to the first bulkhead with respect toa horizontal plane.
 12. The nose structure of claim 9, wherein: the noselanding gear comprises: a trunnion, coupled to the nose landing gearbox; a strut, coupled to the trunnion; an axle, coupled to the strut,opposite the trunnion; and a wheel, coupled to the axle; and with thenose landing gear stowed within the nose landing gear bay, the axle islocated closer to a central longitudinal axis of the aircraft than thetrunnion.
 13. The nose structure of claim 1, wherein the plurality oftransport elements comprises at least one communication line for atleast one of the electrical system, the hydraulic system, theenvironmental system, and the communication system of the aircraft. 14.The nose structure of claim 1, wherein the plurality of transportelements comprises a plurality of operational components, comprising atleast one of electrical components, mechanical components, hydrauliccomponents, and pneumatic components of the aircraft and associated withat least one of the electrical system, the hydraulic system, theenvironmental system, and the communication system of the aircraft. 15.A nose structure of an aircraft fuselage, the nose structure comprising:an airframe; and a floor, comprising: a pressure deck, coupled to theairframe and sloping upwardly in a forward direction with respect to ahorizontal plane, comprising a platform that forms at least a portion ofa pressure boundary delimiting a pressurized space and a non-pressurizedspace and a plurality of support beams that project vertically from theplatform; and a pre-assembled subfloor assembly, installed within thepressurized space, wherein the pre-assembled subfloor assemblycomprises: a floor-panel support, coupled to the plurality of supportbeams of the pressure deck; and a plurality of transport elements,coupled to the floor-panel support, wherein: the plurality of supportbeams space the floor-panel support away from the pressure deck suchthat the plurality of transport elements is located between a portion ofthe floor-panel support and the platform of the pressure deck; and theplurality of transport elements is in communication with to at least oneof an electrical system, a hydraulic system, an environmental system, acommunications system, a propulsion system, a flight control system, anda radar system of an aircraft.
 16. The nose structure of claim 15,wherein: the floor further comprises a plurality of floor panels,supported by the floor-panel support; at least a portion of theplurality of floor panels cover at least a portion of the plurality oftransport elements, and at least the portion of the plurality of floorpanels is removable from the floor-panel support to access at least theportion of the plurality of transport elements from within thepressurized space.
 17. The nose structure of claim 15, wherein thepre-assembled subfloor assembly is assembled outside of the airframe andis installed within the airframe.
 18. The nose structure of claim 15,further comprising a nose landing gear box that is coupled to theplatform of the pressure deck and to the airframe and that forms aportion of the pressure boundary, wherein: the pressure deck and thenose landing gear box form a wheel well assembly of the aircraftfuselage; and the wheel well assembly and the airframe form a noselanding gear bay located in the non-pressurized space.
 19. The nosestructure of claim 18, further comprising a nose landing gear,comprising: a trunnion, coupled to the nose landing gear box; a strut,coupled to the trunnion; an axle, coupled to the strut, opposite to thetrunnion; and a wheel, coupled to the axle, wherein: the nose landinggear is stowable within the nose landing gear bay; and with the noselanding gear stowed within the nose landing gear bay, the axle islocated closer to a central longitudinal axis of the aircraft fuselagethan the trunnion.
 20. The nose structure of claim 15, wherein: theplurality of transport elements comprises a plurality of operationalcomponents; the plurality of operational components comprises at leastone of electrical components, mechanical components, hydrauliccomponents, and pneumatic components of the aircraft; and the pluralityof operation components is coupled to at least one of the electricalsystem, the hydraulic system, the environmental system, and thecommunication system of the aircraft.